Telnet is a network protocol used to virtually access a computer and provide a text-based communication channel based on two-way collaboration between two machines.
To create remote sessions, a user command follows the Transmission Control Protocol/Internet Protocol (TCP/IP) network protocol.On the Web, Hypertext Transfer Protocol (HTTP/HTTPS) and File Transfer Protocol (FTP) allow users to request specific files from remote computers, while through Telnet, users can log on as regular users and access applications and data on that computer with privileges granted to specific users.
An example of syntax for a Telnet command request is as follows:
The result of this request will be an invitation to log on with a user ID, after which the program will ask the user for a password.If accepted, the user is granted access to the remote host.
Telnet is most likely used by program developers, students, and anyone who needs to use certain applications or data on a remote machine.
History of Telnet
Telnet was initially run over Network Control Program (NCP) protocols.It was later named Teletype Over Network Protocol or TONP.While it was used informally for a while, it was officially announced in newspapers published on March 5, 1973.
In early formats, Telnet used the American Standard Information Exchange Code(ASCII),transmitted over an 8-bit channel, to enable remote computers to communicate with basic text.
Over time, several Telnet extensions were created.Telnet has been used as a tool for programmers for decades.The first version of Telnet was created in the 1960s for the Advanced Research Projects Agency Network (ARPANET), the pioneer of the modern internet.It was one of the first tools created to connect computers remotely over long distances.A Telnet protocol was developed by researchers and professionals in 1971, followed by the Telnet system in 1983.
How Telnet Works
Telnet is a type of client-server protocol that can typically be used to open a command line on a server on a remote computer.Users can use this tool to ping a port and find out if it is open.Telnet works with a virtual terminal connection emulator or an abstract instance of a connection to a computer, using standard protocols to act as a physical terminal connected to a machine.FTP can be used with Telnet for users who are trying to send data files.
Users connect remotely to a machine using Telnet, sometimes called Telneting.They are prompted to enter a combination of user name and password to access the remote computer, which makes the command lines work as if they were logged on to the computer in person.Despite users' physical location, their IP addresses will match the computer they are logged on to, not the computer used to physically connect.
Telnet can be used for various activities on a server, including editing files, running various programs, and checking emails.
Some servers enable remote connections by using Telnet to access public data to play simple games or search for weather reports.Many of these features are available for nostalgic entertainment or because they are still compatible with older systems that need access to certain data.
Users can also connect to any software that uses text-based, unencrypted protocols through Telnet, from web servers to ports.Users can open a command prompt on the remote machine, type the word telnet and the name or IP address of the remote machine, and ping the port to see if the telnet connection is open.When an open port shows a blank screen, an error message that states that the port is connected means that it is turned off.
Telnet is not a secure protocol and is not encrypted.By following a user's link, anyone can access a person's username, password, and other private information written in plain text through a Telnet session.This information can provide access to the user's device.
SSH and Other Protocols
Some modern systems enable only command-line connections through Secure Shell (SSH), an encrypted tool similar to Telnet, or a virtual private network (VPN).Due to security concerns, many professional organizations require the use of SSH instead of Telnet.SSH is the most widely used alternative, largely because it encrypts all traffic through the communication channel.
Also, unlike new protocols, Telnet does not support graphical user interfaces (GUI's), which makes it incompatible with many modern programs, from spreadsheets and web browsers to word processors and simulation software.Because these programs run complex graphical interfaces, large amounts of data, especially visual data, are lost through a Telnet session connection, but SSH and similar protocols do not have these losses.